This invention is concerned with a mould arrangement for use in a cyclicly operating glassware forming machine.
In a glass container manufacturing machine of the so-called "individual section" type, a number of container making units or sections are arranged side by side, are fed with glass from a common source, and feed their output to a common conveyor. Each of these sections has at least one blank or parison mould in which a parison is formed from a gob of molten glass delivered to the mould, and at least one final or blow mould in which the parisons are blown to the shape of the required container. The blank mould comprises two side portions which are mounted on supporting arms which are movable to move the side portions towards one another in to a closed position in which the side portions co-operate to form a mould cavity and to move the side portions into an open position to allow moulded parisons to be removed from the mould. When the side portions are in their closed position, a funnel guides a gob of molten glass into the mould cavity through an upwardly facing opening of the cavity. After the gob has entered the mould cavity, a baffle is positioned on the mould to close the opening of the mould cavity and the parison is formed either by blowing the gob to the shape of the cavity or by pressing a plunger into the gob, in both cases the parison forming mechanism is located beneath the mould cavity. The final mould of the machine also comprises two side portions which are movable between open and closed positions thereof, in the closed position the side portions co-operating with a fixed bottom plate to define a mould cavity. The side portions are moved to their closed position while a parison is between them so that the parison is enclosed in the mould cavity and a blowhead is introduced which blows air through an upwardly facing opening of the cavity so that the parison is caused to expand and take up the shape of the mould cavity. The side portions of the final mould are then moved to their open position after removal of the blowhead so that the finished container can be removed from the mould.
Since the moulds of an individual section type machine absorb heat from the glass at a rate which is faster than the heat can be dissipated to the surrounding atmosphere without additional cooling, the moulds of such a machine are supplied with cooling means which cool the mould so that it remains at a substantially constant temperature during successive cycles of operation of the machine. Because the sections of the machine need to be close together, for reasons of glass supply, only very limited space is available around each mould for the provision of cooling means. One solution to this problem is to feed the cooling air through the frame of the machine section to a vertical cooling stack which is provided with nozzles which direct air on to the outside of the mould. This solution, however has the disadavantage that the arms supporting the side portions of the mould interfere with the flow of air to the mould and also it is difficult to provide differential cooling around the mould as may be required. Furthermore, such cooling stacks are a source of undesirable noise. In another type of cooling means, the cooling air is supplied through the supporting arms of the side portions of the mould to a chamber around the mould or to passages within the mould. This type has the disadvantage that it requires expensive machining of the arms, to allow both for the movement of the arms and for the flow of the cooling air. Furthermore, as a seal has to be provided between the arm and the side portion of the mould, delays occur in changing moulds.
In the specification of U.S. patent application Ser. No. 527,589 filed Aug. 29, 1983 in the name of T. V. Foster there is described a mould arrangement in which cooling air can be supplied to side portions of the mould without the cooling air passing through the supporting arms. In this mould arrangement, the passages in each side portion of the mould each have an entrance in a bottom surface of that side portion and the arrangement also comprises a plenum chamber and air supply means arranged to supply mould cooling air to the plenum chamber for a predetermined period in each cycle of operation of the machine during which the side portions are in their closed position, the plenum chamber extending beneath the side portions and having exits which, when the side portions are in their closed position, communicate with the entrances of the passages so that air can leave the plenum chamber and pass through the passages. This arrangement provides a satisfactory way of providing cooling for the final or blow mould of the machine but is not readily applicable to the blank mould since the plenum chamber cannot extend beneath the mould as this area is occupied by the plunger mechanism or the air blowing mechanism used to form the gob into a parison.
It is an object of the present invention to provide a mould arrangement in which cooling air can be supplied to side portions of a blank mould without the cooling air passing through the supporting arms and in which the above mentioned disadvantages are overcome.